A wafer defect inspection apparatus that is configured to inspect a defect that is on the surface or rear face of a wafer or inside a wafer has been known. For such a wafer defect inspection apparatus, one surface of the principal surfaces of a wafer is irradiated with an infrared light, the other surface of the principal surfaces of the wafer is imaged, and an image analysis processing is executed to the image for instance. By this configuration, a defect of a wafer is inspected.
For such a defect inspection of a wafer, the actual imaging is carried out while sampling a part of wafers for every lot in which a plurality of wafers is brought together for instance. By this configuration, an imaging condition (recipe) is decided for setting an average gray level of an image of a wafer in the range in which a defect can be detected in an appropriate manner (a defect detectable range). By using the recipe, a defect inspection is then carried out to all wafers in the lot.
As a technology related to an imaging in the case of a detection of a defect that is on the surface or rear face of a wafer or inside a wafer by using a transmitted light illumination, a technology has been known in which a value of a specific resistance of a wafer is obtained in advance, an intensity of illumination of an infrared light illuminating means is adjusted according to the value of a specific resistance, and a sensibility to an infrared light of an imaging means is adjusted (see Patent Literature 1).